Screw capable of conversion into a fixed wing



E. A. PERRIN Sept 29, 1936.

SCREW CAPABLE OF CONVERSION INTO A FIXED WING Filed March a, 1934 2 Shoots-Sheet 1 2 1936- E. A. PERRIN 2,055,535

SCREW CAPABLE OF CONVERSION INTO A FIXED WING- Filed March 8, 1934 2 sheets -sheet 2 i Ft 113. 1 Fig INVBYTOR [Jawarl fiz ad Terr) By 2 Patented Sept. 29, 1936 UNITED STATES PATENT OFFICE WING Edouard Alfred Pen-in, Le Vesinet, France Application March 8, 1934, Serial No. 714,703 In France March 17, 1933 '7 Claims.

This invention relates to air screw propellers which can be converted into fixed planes, and has for its object an improved driving or sustaintaining means adapted to rotate in the surrounding atmosphere and means using the force resulting from the rotation produced by the action of their relative movement in a surrounding fluid, such as, forexample, wind mills, air propellers or similar apparatus.

In connection with supporting systems for machines for aerial navigation, suggestions have been made previously to provide such machines with two supporting propellers adapted to revolve in opposite directions, means being provided for locking and unlocking'so as to lock them' in a suitable position, or to allow their rotation at the pilots will, while means are also provided for varying the incidence of the blades of the propellers.

According to the present invention an air screw propeller or the like is mounted on a shaft to which it is capable of being locked so that it may act as a sustaining plane, and from which it can be released to permit its rotation about the said shaft, whereas the incidence of the blades of the propeller can be varied when the propeller is adapted to rotate. More specifically the blades or the propeller are connected to a hub capable of being locked and unlocked from the shaft on which it is mounted by a hinge so as to enable the normal theoretical axis of the blade to be moved from a horizontal position to a position inclined relatively to the axis of rotation about an axis at right angles to the axis of 35 rotation.

The invention will now be described with reference to the accompanying drawings, wherein:

Figure 1 shows a perspective view of an air screw propeller;

40 Figure 2 shows a sectional view of one form'of a device for connecting and disconnecting a rotary member to and from a stationary member taken on line 2-2 of Fig. 12;

Figure 3 shows a similar view of the device in 45 Fig. 2 in. the disengaged and locked position;

' Figure 4 shows a detail view of a form of actuating mechanism actuated as a result of relative rotary movement between a rotary member and a stationary member, with a device where- 50 by the mechanism may be actuated independently of the relative rotation;

Figure 5 is a cross section of a blade of an air screw propeller on the line 5-5 of Fig. '7;

Figure 6 shows a detail view of an arrange 55 ment for causing an actuating mechanism to move into its end positions with a snap action and for locking the actuating mechanism in these positions;

Figure '7 is a sectional view of a blade of an air screw propeller and its mounting taken. on 5 the line 1-1- of Fig. 8;

Figure 8 is a vertical sectional view taken on the-line 8-0 of Fig '7;

Figure 9 is a section of a roller bearing taken for example, on the line 99 of Fig. 7; 10

Figures 10 and 11 show detail sectional views of a locking device for the blades in the locking and unlocked positions, respectively, taken on line I0i0 of Fig. 7;

Figure 12 is a section on the line I2-I2 of 15 Fig. 8 to a larger scale;

Figure 13 is a fragmentary section on the line I3-I3 of Fig. 12 to a larger scale, and.

Figure 14 is a fragmentary section on the line I4-I4 of Fig. 12 to a larger scale.

As shown in Fig. 1 the blades of an air screw propeller, according to the present invention, after the propeller has been released for rotary movement, are capable of having their incidence varied by tilting them about their theo- 25 retical axis IOI. This theoretical axis, normally secured to the axis of rotation I02 when the propeller serves as a sustaining plane, is capable of being more or less inclined relatively to the axis I02 so as to extend'along the line I03.

The angle of inclination I04 of the theoretical .axis 'IOI relative to the axis I02 is so selected that during the normal rotationof the propeller the sustaining force I05 acting on the blade and the centrifugal force I 06 produce a resultant 5 I01 extending substantially along the center line I03 of the blade. The angle of inclination I08 between the center line I03 and the theoretical axis IN is so selected that during normal rotation of the propeller the centers of the sustain- 40 ing and centrifugal forces are located behind the theoretical axis I0i.

Under these conditions there corresponds to every increase in the sustaining force, acting on the blade and opposing centrifugal force, a lifting of the portion of the blade behind the theoretical axis I! and consequently a correlative and correcting reduction of the incidence of the blade relative to its path through the surrounding atmosphere. Conversely any reduction in the sustaining -force increases relatively the action of centrifugal force and produces a lowering of the rear portion of the blade, thus producing a correlative and corrective increase of the incidence. u

This correcting effect takes place automatically irrespective of the cause of the initial variation of the sustaining force I acting on the blade, that is to say, whether this action is due to the action of the surrounding atmosphere, or whether it is due, for example, to the forces of inertia known as gyroscopic forces or compound centrifugal forces.

When the theoretical axis IOI passes slightly in front of the centers of the sustaining and centrifugal forces, the variation of the correcting incidence reaches a high amplitude relative to that of the correlative variation of the inclination of the center line I03 relatively to the axis of rotation I02. Neglecting these latter variations, which are of small amplitude, the sustaining force I05, during normal rotation, is substantially constant relative to the centrifugal force I06 acting on the blade. This arrangement therefore substantially annuls automatically any variations in the sustaining force I05, which would otherwise produce, during the normal rotation of the axis I02, variations in the relative speeds of the blades through the surrounding atmosphere, or even gyroscopic inertia forces created by any possible rotation of the propeller about axes other than the axis I02.

This arrangement therefore eliminates automatically in practice couples which would disturb the equilibrium of the apparatus and which are derived from the sustaining propeller, which itself is fixed, irrespective of the method for producing rotation, that is to say, whether rotation is produced by a separate motor which drives the propeller mechanically, or as a result of autorotation, for example, by lateral movement in the surrounding atmosphere.

It is also possible to vary the initial normal angle of inclination of the center line I03 rela tively to the axis I02 by a graduated action of elastic devices, such as the tie wire I09 by which the blade is connected to the axis of rotation I02.

Finally, the position of the theoretical axis IOI may be fixed relatively to the axis I by securing a point IIO, which is located in front of the axis II, to the axis I02 by two stays III and H2. One of these stays, preferably the stay II2 which normally supports a smaller force than the lower stay III, may include an elastic element which enables it readily to lend itself to slight variations in length and thus to facilitate orienting the blade.

The point of junction II3 of the blade to its hub is located in such a position that the blade can transmit effectively to the hub the various forces acting on the blade, thus reducing the work of the stays III and H2. Thus the blade may, for example, be rotatably mounted on a shaft II4 which is at right angles to a hinge II5 on the hub.

In Figs. 7 and 8 the hub of the propeller is secured to a sleeve I32 (Fig. 8) capable of rotating on a shaft I33 which is secured to the apparatus by means of a casing I6I and two lateral webs I62. The rotation of the sleeve is facilitated by circular races I63, I04 on the sleeve with which engage rollers projecting from the shaft I 33 in the planes 25-25, Fig. 8. The vertical downward thrust is taken up by two rollers I65 mounted on the sleeve I32 and running on a shoulder I66 on the shaft I33. The dead weight is supported by an upper axial bearing I61.

The inner sections I69 of the blades are connected to the hub at I 68 by a group of four hinges corresponding with the hinge II 5 in Fig. 1.

Each of these sections carries the longitudinal tubular shaft II4. The middle section I10 of each blade can turn about the shaft M4 by means of circular roller tracks I1I, I12 with which co-operate rollers projecting from the tubular shaft II4, as shown to a larger scale in Fig. 9.

In the outer end of the shaft H4 is mounted a rod I13 which is secured to the blade by keys I14 and a central block I15.

The stays III, II2 connect the sleeve I32 to tubes I16 which pass across the middle section of the blade and determine the position of the theoretical axis MI.

The elasticity of the stay II2 may be provided for by resiliently mounting the upper pulleys I18, or by means of resilient rings l19 which are arranged between the pulleys I18 and the lower winch drums I80.

The blades, initially set at I8I, when the propeller is to be used as a sustaining plane, are raised to the full line position when the propeller is to be used as a helicopter, or is to be driven by auto-rotationby means of winches I80.

One of the winch drums may be constructed as a cam so as to take into account for the movement of the tubes I16 during the lifting movement.

Before the blade can be moved into the inclined position it is necessary to release the engagement between the inner section I 69 from the hub and also the engagement between the middle section I10 and the inner section I69, so as to enable the blade to have its incidence varied for use as a helicopter or air propeller. The engagement between the middle section I10, the inner section I69 and the hub is, for the sake of convenience, hereinafter referred to as the in ternal locking device". This internal locking device is shown in detail in Figs. 10 and 11 in the locking andreleased positions respectively. This device consists of hinged bolts I82 which engage with tubular housings in the middle sections I10 and in the inner sections I69 of the blades. These bolts are held in the locking position by connecting rods I83 actuated by a central block I84 which is secured to a pulley I85 operated by a cable I86 (Figs. '1 and 10). Between the bolts I82 and the rods I83 are provided hinges I 81, which, in the released position, are brought into alignment with the hinges I68 so that the blade can turn on the latter.

The internal locking device may be released before the sleeve I32 has been disengaged from the shaft I 33 or after this disengagement and mechanism for this purpose is shown in Fig. 4.

In Fig. 10 the bolts I82 are shown in the locking position, the connecting rods I83 being in alignment therewith, in which position they are held by the central member I84 which has been actuated by the cable I86 and pulley I85.

Fig. 11 shows the unlocked position after the pilot has rotated the member I84 through a sufficient angle to cause the connecting rod I83 to withdraw the bolt I82 from its housing in the middle section I10 (Fig. '7), thus disengaging the latter from the inner section I69, while at the same time bringing thehinge I 81 into line with the hinges I68.

In Fig. 4 a roller I30 is mounted in a fork I35 pivoted to the sleeve I32 mounted for rotation on the shaft I33. This roller I30 co-operates with a cam I34 fixed to the shaft I33 which is so shaped, that after a predetermined amount of rotary movement of the sleeve I32 the roller I30 rises in the cam surface I34 and thus lifts the fork I35 which through the medium of a rod I36 imparts an angular movement to a pulley I31. Around this pulley I3I passes a cable I38 (I86 in Figs. 10 and 11) which actuates the pulley I85 and thus the block I84- of the internal locking device. When the internal lock- 7 ing device is to be actuated before the sleeve I32 is disengaged from the shaft I33, the pilot actuates a beilcrank lever I39 so as to raise an auxiliary cam I40 which lifts the roller I30. In this manner the internal locking device is rendered independent of the rotation of the sleeve I32.

When the roller I30 engages with the recessed portion of the cam I34 or the bellcrank lever I39 is moved in the opposite direction, and the internal locking device is moved into the engaging position.

In Fig. is shown an arrangement whereby the leading edge of a blade can be changed to a trailing edge and vice versa. As shown, there are provided two channel members I, I42 which extend longitudinally along the greater portion of the edges of the blade; these members I, I42 are connected together by transverse members I43 which pass through a central frame I44. Ribs I45, I46 to which the fabric of the blade is secured, are hinged at I41, I48 to lugs secured to the frame I44. The ribs are drawn togetheron opposite sides of the hinge points I41, I48 by springs I49 whereby the ends of the ribs are held against the members I4I, I42. The transverse members I43 are moved transversely to the blade by means of cables I50 secured to the said members I43 and passing around pulleys I5I, I52. The cables I50 then pass through the central frame I44 and are attached to a pulley III. This pulley is adapted to be actuated by a mechanism similar to that shown in Fig. 4. In this case the pulley is actuated directly by the cable I38.

In Fig. 6 is shown an arrangement for ensuring the movement of the pulley IlI into its and positions and thus locking the members I4I, I42 in the position into which they have been moved In this construction the cable I53, corresponding with the cable I38 in Fig. 4, passes around a pulley I56, keyed to the same shaft as the pulley I". To the shaft of the pulley I56 is keyed a fork I58 carrying a roller I5'I which is secured to the sleeve I32. The cam is provided with recessed portions adapted to receive the roller I51 in its end positions indicated at I54, I55? As a result of the spring mounting of the cam I59 the roller I51 moves into its end position with a snap action and as a result locks members I4I, I42 in position. The arrangement shown in Fig. 6 may also be provided in combination with the mechanism shown in Figs. and 11.

As shown in Fig. 12 the winches I60 are mounted at the lower end of the sleeve I32. The winches H80 are operated by bevel wheels on an intermediate shaft I90 and a driving shaft I9I. The latter can be driven through a clutch, similar to that hereinafter described with reference to Fig. 3 by a shaft I92 when the clutch is engaged as a result of upward movement applied at the annular groove I21. The shaft I92 is driven by the engine of the machine or by an air screw propeller which drives a shaft I93 connected to the shaft I92 by bevel wheels for the purpose of rotating the sleeve I 32. a

The sleeve I32 is unlocked by actuating a rod I94 (Fig. 12) and a bell crank lever I95. The latter, through the medium of a rod I96 (Fig. 14) actuates a lever I91, keyed to a shaft I99 carried by 9. lug secured to the sleeve 200 which is secured to the casing I6I. To the shaft I99 is also keyed an arm I98 provided with a tooth 202 which engages with slots in a ring 2!, secured to the sleeve I32, and in the sleeve 200 fixed to the shaft I33. When the rod I94 is pulled this tooth 202 is disengaged from the slots, thus releasing the ring 20I and consequently the sleeve I32. A further locking device is provided at 203 (Fig. 12). This locking device has a tooth 204 which is mounted in a shaft 205 and which can be moved into an upwardly directed position by the pilot by means of a lever 206 and a rod 201. In this position the tooth 204 engages with a slot in a member 208 which is secured to the sleeve I 32 by a threaded rod 209. By means of this arrangement it is possible, after the parts have been locked together, to take up any play between the member 208 andthe sleeve I32 so as to obviate any deleterious vibrations of the locked system.

A male cone clutch member 2I0 is mounted on the shaft I92 and co-operates with a female cone clutch member 2 loosely mounted on the shaft I92. The female member 2 is normally urged into the engaging position by a weak spring 2I2 and is connected to a chain wheel 2I3 by a dog clutch. The chain wheel 2I3 .drives a chain located in the plane 2626 and this drives a ring 2 mounted on a roller 2I5 carried by the spindle I33.

' The clutch members M0, 2 can be engaged by the pilot by actuating the lever 2I6 through the medium of a rod 2I'I. When the rod 2I'I is pulled, the lever 2I6 leaves a shoulder 2I9 on a rod 2I8, which latter is then pulled downwardly by a spring 220 which was previously compressed. The upper end of the rod 2I8 acts on a pair of levers 22I, pivotally mounted at their other end and through the medium of rollers 222, carried by the levers 22 I and engaging with an annular groove in the female cone 2i I, force the latter into engagement with the male cone 2"), whereby the ring 2 is rotated by means of the chain in the plane 26, 26.

In its upper end the ring 2 is provided with recesses 223 (Fig. 13) with which co-operate driving pawls 224 pivoted at 225, to the ring I32, which they are adapted to drive through stops 226. The notches 223 are so shaped that when the sleeve I32 is rotated in one direction, viz: to the right in Fig. 13, the pawls 224 move into the dotted position 22'! against the action of the spring 228 and thus do not drive the ring 2. The spring 228 normally serves to hold the pawls 224 against the'stops 226.

In Figs. 2 and 3 is shown a simplified form of the driving mechanism shown in the planes 22 in Fig. 12. In Figs. 2 and 3 the drive from a suitable prime mover is transmitted by a chain, not shown, to a. sprocket wheel II6 formed integral with a sleeve II'I rotatably mounted in bearings II6 provided on a fixed part of the apparatus. The sleeve II I is provided internally with a longitudinal groove with which engages a key H9 projecting from a shaft I20 slidabiy, but non-rotatably mounted in the sleeve Ill. The shaft I20 is normally urged upwards by a spring I2I. At the upper end of the shaft I20 is provided a clutch member I22 having three radial dogs adapted to co-operate with corresponding recesses or notches in a clutch-member I 23 adapted to transmit its movement to the sleeve I32. The member I23 is mounted in bearings I26 on the sleeve I32, its lower end passing through a sleeve I24 normally urged downwardly by a spring I25.

In the engaged position of the members I22 and I23, shown in Fig. 2, the sleeve I24 has been pushed upwardly by the member I22 against the action of the spring I25, thus disengaging teeth I28 on the member I24 from corresponding teeth on the lower bearing I26, so as to permit of rotation of the latter and of the member I23 to which it is keyed.

In order to disengage the members I22, I23 the pilot actuates suitable rod mechanism engaging with a circular groove I21 at the lower end of the shaft I20, whereby this shaft is pulled downward. Upon downward movement of the shaft I20, the dogs of the clutch member I22 are disengaged from the recesses in the member I23, while at the same time the non-rotatable sleeve I24 is forced downwardly by the spring I25, whereby the teeth I23 thereon engage the teeth of lower bearing I28, thus locking the sleeve I24 against rotation. The sleeve I24 engages with the member I23 by means of teeth I29, thus also looking this member.

In order to provide for substantially frictionless -movement between the relative rotating parts, roller bearings are provided in the planes 9--9, 25-25, Fig. '7, 25-25, Figs. 8 and 12, and 2626, Fig. 12. These bearings are of substantially similar construction and will be described with reference to Fig. 9, which is a section on the line 9-9 of Fig. '7 on a larger scale. As shown, the central frame I44 of the blades is provided with a circular roller track with which co-operate four rollers I88 mounted on shafts I 89 carried by lateral plates forming stays for the tubular shaft H4. The rod I13 is located at the center of these plates.

As will be readily understood the arrangement shown in Fig. 9 can be directly applied to the roller bearings in Figs. 8 and 12. By means of the arrangements above described it will be seen that the propeller may be used, when locked in position, that is to-say, when prevented from rotation as a sustaining plane. When released the blades of the propeller may be inclined relatively to the axis of rotation, while the trailing edge of one or both blades may be changed into a leading edge as may be required. Aircraft provided with apparatus as above described is capable of acquiring high travellingspeeds with an economy in the consumption of power, when the propeller is fixed, while it can land within acomparatively small area in an aerodrome or on uneven ground at a-comparatively low speed.

The actuating and releasing devices are all controlled from the pilots cabin.

I claim as my invention:---

1. A combined air screw propeller and sustaining surface comprising a hub, a plurality of blades having separate inner and middle sections, a hinge connecting the inner section of each blade to the hub for movement relative thereto about an axis tangential to an are described about the axis of rotation of the hub, and means connecting the middle section of each blade to its inner section to provide for adjustment of the incidence of the middle section.

2. A combined air screw propeller and sustaining surface comprising a hub, a plurality of blades having separate inner and middle sections, a hinge connecting the inner section of each blade to the hub for movement relative thereto about an axis tangential to an are described'about the axis of rotation of the hub, means connecting the middle section of each blade to its inner section to provide for adjustment of the incidence of the middle section, a shaft supporting said hub, means for detachably locking said hub to said shaft, means for locking said inner section to said middle section and to said hub, and lock-actuating means operable for releasing the lock between said propeller sections and hub before releasing thelock between said hub and shaft.

3. An air screw propeller according to claim 2 wherein the lock-actuating means includes an actuating member, a cam and a roller co-operating with the cam for rocking said member.

4. An air screw propeller according to claim 2 including a one-way ratchet mechanism between said hub and shaft.

5. An air screw propeller according to claim 2 wherein the actuating means includes an 'actuating member and snap action means for moving the actuating member to its extreme positions.

' 6. A combined air screw propeller and sustaining surface, comprising a vertical shaft, a hub mounted on said shaft, means for detachably locking the hub to said shaft, a plurality of blades, a universal hinge connecting each blade to said hub, and means for moving the normal theoretical axis of the blades from a horizontal position to a position inclined relatively to the axis of rotation, said moving means including a driving shaft and a driven shaft and a clutch adapted to be controlled by the pilot for coupling said shafts.

7. An air screw propeller according to claim 6, including a one-way ratchet mechanism between said hub and shaft.

EDOUARD ALFRED PERRnw. 

